Hello Johnson,
I can’t make any recommendations here on what you should choose Johnson, just choose the option that fits best for you per the needs of your workload that you need to deploy. I will try to answer your questions as best I can.
1- The stateful container requires less than 10 Gigs of persistent disk; can this run on Google Cloud Run?
Cloud Run does support container workflows and standards so this should be possible.
2- Ideally it would have an A record in CloudDNS that points to a static IP of this container; is this supported in CloudRun? If my estimates are correct, GCP load balancers are WAY too expensive; over $200 per year!!!
Cloud Run does support mapping to custom domains.
3 - Does CloudRun support replicas?
Yes, Cloud Run is built to run on GKE so replicas are supported.
You can find more documentation in the article below if needed.